The present invention relates to an improvement to small vehicles known as remotely operated vehicles (ROVS) which move along a conductor of a power line or an overhead earth wire.
The present invention also relates to a de-icing tool which is mounted on a remotely operated vehicle.
ROVs are known devices which are used to take measurements of electric, physical and/or environmental parameters and to check certain conditions associated with the power lines mounted between pylons.
The following documents describe known ROVs: U.S. Pat. No. 4,904,996 (FERNANDES); U.S. Pat. No. 5,901,651 (BOYD); and PCT patent application WO 94/18046 (SCOTT).
The main problem associated with known ROVs is their difficulty to generate a traction force (or pulling force) sufficiently strong for moving along a power line. Typical power lines can be made out of steel or aluminum and can have various diameters. In some cases, the line can be wet and, in other cases, it can even be covered with ice residues. The problem of traction arises particularly from the choice of materials of which are made up the wheels.
A known ROV has a weight of approximately 110 lb and a measured pulling force of 75 lb. This ROV has only two traction wheels of simplistic form. It measures about 25 in.xc3x9710 in.xc3x9714 in. The size of this ROV is somewhat large, and consequently cumbersome for handling and for using on live lines. Furthermore, this ROV is not designed for moving along a live line, which can be wet or covered with ice residues.
De-icing tools for cables are described in the following documents: U.S. Pat. No. 4,227,304 (OKAMURA) and JP-1081613 (MATSUMOTO). These de-icing tools are not adapted for being mounted on an ROV.
A first object of the present invention is to provide an ROV having a traction force sufficient for operating on a live line, which is wet or covered with ice residues.
A second object of the present invention is to provide an ROV which is smaller than most known ROVs, which is easier to handle, and which facilitates the operations of cleaning, de-icing and inspection of power lines.
A third object of the present invention is to provide an ROV which can be move along a live line and which can be easily be installed thereon.
A fourth object of the present invention is to provide an ROV which can be adapted to fit different conductors diameters, and can cross conductor joints of live lines.
According to the present invention, there is provided a vehicle for use on a live line, comprising:
three coplanar traction wheels mounted on a frame and spaced along a first longitudinal axis parallel to the live line and above therefrom;
two movable coplanar pressure wheels mounted on the frame and spaced along a second longitudinal axis parallel to the line and below therefrom;
a driving motor mounted on the frame, for driving the traction wheels, the motor having a source of energy;
pressure means mounted on the frame and coupled to the pressure wheels, for maintaining the line squeezed between the traction wheels and the pressure wheels; and
control means coupled to the motor for controlling the motor; and thereby in use, the vehicle is moved along the line.
Another object of the present invention is to provide a de-icing tool for breaking the ice which has accumulated on a live line or on overhead earth wire.
According to another aspect of the present invention, there is also provided a de-icing tool mounted on a vehicle for use in a live line, comprising:
a collar having two parts opening and closing around the line, the collar supporting blades concentrically spaced apart from each other and forming an open cone in a forward moving direction of the vehicle.